Estimation of the Contributions of Various Mechanisms to the Deformation Resistance of Cu–12 at % Al Single Crystals

The structural evolution of Cu–12 at % Al alloy single crystal during plastic compressive deformation is studied. Data on a flow curve, the stages of deformation, and the relation between the stages and the type of substructure are presented. The substructure parameters are quantitatively measured. The results are presented as a diagram of the fraction of substructure versus the dislocation density. The strain dependences of the distances between nonreacting intersections of dislocations, interdislocation reactions, obstacles, and dislocations are revealed. Special attention is paid to a quantitative estimation of the contributions of local stoppers and long-range elastic stress fields to the resistance to shear-forming dislocations and the contributions of slip and twinning to deformation.